b-u bbb bbg bbk bbn bbo bbr bbu bgb bgg bgk bgn bgo bgr bgu bkb bkg bkk bkn bko bkr bnb bng bnk bnn bno bnr bnu bob bog bok bon boo bor bou brb brg brk brn bro brr bru bub bug buk bun buo bur buu gbg gbk gbn gbo gbr gbu ggb ggg ggn ggo ggr ggu gkb gkn gko gnb gnn gno gnr gnu gob gog gok gon goo gor gou grb grg grk grn gro grr gru gu- gub gug guk gun guo gur guu kbb kbk kbn kbo kbr kbu kgb kgo kgu kkb kkk kkn kkr kku kn- kng knk knn kno knr knu kob kog kok kon koo kor kou krg krk krn kro krr kru kub kug kuk kun kur kuu nbb nbg nbk nbn nbo nbr nbu ngb ngg ngk ngn ngo ngu nkk nkn nko nkr nku nnb nng nnk nnn nno nnu no- nob nog nok non noo nor nou nrb nrg nrk nrn nro nrr nru nub nug nuk nun nuo nur nuu ob- obb obg obk obn obo obr obu ogg ogn ogo okb okg okk oko okr oku on- onb ong onk onn ono onr onu oo- oob oog ook oon ooo oor or- orb org ork orn oro orr oru ou- ouk oun ouo our rbb rbg rbk rbn rbo rbr rbu rgb rgg rgk rgn rgo rgr rkb rkg rkk rko rku rnb rng rnn rno rnr rnu rob rog rok ron roo ror rou rrb rrg rrk rrn rrr rru rub rug ruk run ruo rur ruu ubb ubg ubk ubn ubo ubr ubu ugb ugg ugk ugn ugo ugr ugu ukb ukk ukn ukr uku un- unb ung unk unn uno unr unu uob uog uok uon uoo uor ur- urb urg urk urn uro urr uru uug uun uur uuu